There is no need guessing. Find out if the pregnancy tests are available in your area. Even the most affordable ones can show you if you are pregnant. Mind that the use of pregnancy tests delivers reliable results only 2-3 weeks after the unprotected sex. They should not be used to identifed 1-2 week pregnancy. You may also consult a doctor, do blood tests or run Ultra Sound to find out for sure. Missing period may indicate of pregnancy, but it can also signify some health problems of the reproductive system. So even if you are not pregnant, you should pay attention and get medical consultation.